This list highlights topics for which some care must be used when
comparing 1990 and 2000 Census data. The information
was obtained from the Bureau of the Census via the State Data Center. The
list is not meant to be definitive. Users are encouraged to do their own
evaluation using the technical documentation publications:
- 1990 Summary Tape File 3 Technical Documentation (complete in pdf)
- Appendix B: Definitions of Subject Characteristics (text format)
- 2000 Summary File 3 Technical Documentations (complete in pdf)
- Race
Race categories for 2000 are not directly comparable to earlier years. For guidance about doing a comparison see the Race and Hispanic Origin entry on the Census 2000 page. Below are the factors that make comparisons difficult.- The basic race categories changed. "Asian and Pacific Islanders" were one category in 1990 and now they are two categories: "Asians" and "Native Hawaiian or Pacific Islander."
- In 2000 a person could choose one or more races so the same person can be counted in totals for more than one race.
- Hispanic Origin
This question was asked differently. The Hispanic origin question was asked before the race question in 2000 and after the race question in 1990. When asked to choose a detailed race the sample entries shown on the form were different between 1990 and 2000. - School
Enrollment
Difficult to compare because the questions were asked differently. 2000 enrollment data is more detailed than 1990. - Marital Status
Defined the same way though the question was asked on the short form in 1990 and on the long form in 2000. - Unmarried Partners and Same Sex Partners
Refer to the Census Bureau's note on how processing makes direct comparison between 1990 and 2000 difficult. - Income
These numbers are comparable after adjusting for inflation. The questions ask for annual income for 1989 and 1999 so the CPI index change between those years applies. See the BLS CPI web page and select CPI_U. - Industry and Occupation Codes
These are not comparable. Refer to the Industry and Occupation Classification System for details. - Housing Value
These numbers are comparable after adjusting for inflation. The questions ask for value in 1990 and in 2000 so the CPI index change between those years applies. See the BLS's CPI web page and select CPI_U. - Grandparents as caregivers
This is a new category for the 2000 census. - Language Density
This is a new category for the 2000 census derived from the "language spoken at home" question. - Veteran Status
The universe has changed from civilian population 16 years and over to civilian population 18 years and over. The impact on the numbers should be minimal. - Disability Status
Not easily comparable - Visually Impaired
This is a new category for the 2000 census. - Learning Disabled
This is a new category for the 2000 census. - Region of Birth of the Foreign Born
This will be comparable though in 1990 it was reported only on STF4 and not STF3. The 1990 numbers were not adjusted for those who did not report while in 2000, non-responses to this question were allocated. Also for 2000, those born at sea were not reported. With the collapse of the Soviet Union, former members of the Soviet Union are included under Europe keeping in place with the UN guidelines. Northern America includes Canada, Bermuda, Greenland but not the US since the category is foreign born. - Children ever born (fertility)
Question asked in 1990 and not in 2000 - Source of Water
Question asked in 1990 and not in 2000 - Condominium Status
Question asked in 1990 and not in 2000 - Year Last Worked
Question asked in 1990 and not in 2000 - Sewage Disposal
Question asked in 1990 and not in 2000
The following list highlights selected topics for which care should be taken when trying to compare 2000 data to 1990 data.
